fastigium

An apex or summit; culmination.

A pediment or gable end.

The most intense phase of a disease, especially a fever.

[W]e find that the duration and succession of the febrile phenomena constitute five principal groups. […] 2. Fevers which are essentially continuous in their course (continued fevers), which exhibit but slight daily differences of temperature during their fastigium or acme, and defervesce rapidly (by crisis).